1. Field of the Invention
The present invention relates to a synergistic skin lightening composition. The invention particularly relates to a composition with a combination of skin lightening actives suitable for obtaining improved skin lightening.
2. The Related Art
Melanin is the black pigment of hair and skin and is synthesized from the amino acid tyrosine by melanosomes. Melanosomes are organelles found in melanocytes, a cell type present at the dermis-epidermis junction. Tyrosine is acted upon by an enzyme, tyrosinase, which is the key step in melanogenesis. There have been several reports wherein inhibitors of tyrosinase such as hydroquinone and its derivatives, kojic acid, catechols, mercaptoamines, alpha hydroxy acids and others have been used in cosmetic compositions to regulate skin pigmentation.
IN182012 (Hindustan Lever Ltd., 1994), discloses synergistic compositions suitable for topical application to the human skin comprising dicarboxylic acids in combination with ascorbic acid in cosmetically compatible carriers. They also mention that additionally other whitening agents such as niacinamide and/or sunscreens (inorganic and/or organic) may also be present.
Use of alpha-hydroxy acids in cosmetic compounds for imparting various skin benefits such as improving the texture of the skin, increasing smoothness, firmness, moisture content is reported in U.S. Pat. No. 5,658,580 (Chanel, Inc., 1997). U.S. Pat. No. 5,262,153 (Kabushiki, 1993), discloses lactic acid and its derivatives as useful skin whitening agents which act by suppressing melanogenesis by inhibiting formation of tyrosinase.
In the melanosomes melanin is synthesised (polymerized) from monomers and is transferred to the neighbouring keratinocytes. The keratinocytes divide and differentiate and thus transport the melanosome to the surface of the skin. The intensity of the skin colour is directly related to the number, the size, the melanin content, dispersion of melanin, the rate of formation and migration/transfer of melanosomes to the keratinocytes.
Other approaches have been to use niacin/niacinamide or other skin lightening agents which are believed to control dispersion of melanosomes or inhibit tyrosinase.
IN 144276 (Hindustan Lever Ltd., 1975), discloses the combination of niacinamide and a suitable mixture of UV absorbers which absorb in the UV range of 290 nm to 360 nm. IN169917 (Hindustan Lever Ltd., 1989), discloses the use of silicone compound to synergistically enhance the skin lightening benefit obtained from the combination of niacinamide and sunscreens.
The sunscreens that are commonly used in skin lightening compositions maintain skin colour by preventing darkening of the skin due to ultra violet (UV) light. The sunscreens are materials, which absorb incident ultra violet light of the wavelength which produces the tanning and darkening of the skin.
Vitamin B6, also called pyridoxine, is closely related to water-soluble substances such as pyridoxine hydrochloride, pyridoxal, and pyridoxamine, in form and function. Pyridoxine supplementation is used for a variety of skin problems including dandruff, eczema, dermatitis, and psoriasis. It is the active component for a number of anti-aging formulations. JP04009325 (Sunstar Inc., 1992), disclose a beautifying and whitening cosmetic obtained by blending mycelial culture of Ganoderma lucidum Karst. and/or an extract essence thereof with one or more selected from ascorbic acid, retinol, pyridoxine, pantothenic acid, tocopherol, salts and derivatives thereof as an active ingredient. JP60188306 (Shiseido, 1985), discloses a cosmetic composition comprising pyridoxine or a derivative in combination with ascorbic acid for significantly improving the skin whitening effect.
U.S. Pat. No. 5,833,998 (P&G, 1998), discloses topical compositions for regulating the oily and/or shiny appearance of skin comprising an active selected from one or more compounds from the group consisting of niacinamide, pyridoxine, panthenol, and pantothenic acid, in a cosmetically acceptable carrier for said active.
However, none of the prior art teaches a synergistic cosmetic composition comprising vitamin B3, vitamin B6 and anyone of mono-, di- or poly- carboxylic or phenolic acids to obtain improved lightening or reduction of pigmentation of the skin.
It is an object of the present invention to provide a synergistic cosmetic composition comprising vitamin B6, vitamin B3 and any one of mono, di or poly carboxylic or phenolic acids that can lighten the skin significantly.
It is another object of the present invention to provide a synergistic cosmetic composition comprising vitamin B6, vitamin B3 and any one of mono, di or poly carboxylic or phenolic acids useful both for normal skin as well as skin damaged by UVR.
The compositions are also useful in treating freckles, hyper-pigmented skin, blotchy skin, melasmas, cholasmas, age spots, dark circles, etc.